Stroller frame



FIG. 1 is a front view of my ornamental design for a stroller frame;

FIG. 2 is a rear view of the stroller frame of FIG. 1;

FIG. 3 is a side perspective view of the stroller frame of FIG. 1; and,

FIG. 4 is a bottom view of the stroller frame of FIG. 1.

The dotted lines represent a brake handle and cable which form no part of the ornamental design claimed herein. 

The ornamental design for a stroller frame, as shown and described. 